Epithelial and adipose cells isolated from mammary glands of pregnant and lactating rats differ in 11 beta-hydroxysteroid dehydrogenase activity.
Both adipose and epithelial cells isolated from the mammary glands of pregnant and lactating rats show 11 beta-hydroxysteroid dehydrogenase (11-HSD) activity, as measured by conversion of corticosterone to 11-dehydrocorticosterone. Activity in adipose cells from pregnant rats is 3-fold higher than in lactating rats. Epithelial cells from pregnant rats show one-twentieth of the activity of adipose cells, and activity is lower still in epithelial cells from lactating rats. Explants incubated for 48 h extensively metabolized corticosterone to 11-dehydrocorticosterone, and to a much lesser extent to a second unknown metabolite which is found in tissue extracts but not conditioned medium. Mammary gland 11-HSD may thus constitute one of the physiological mechanisms preventing premature milk production in response to glucocorticoids.
Quirk
S J
SJ
Prince Henry's Institute of Medical Research, South Melbourne, Victoria, Australia.
Slattery
J A
JA
Funder
J W
JW
D042842:11-beta-Hydroxysteroid Dehydrogenases; D000273:Adipose Tissue / Q000201:enzymology*; D000818:Animals; D003345:Corticosterone / Q000031:analogs & derivatives / Q000378:metabolism; D004848:Epithelium / Q000201:enzymology; D005260:Female; D006913:Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D007774:Lactation / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000201:enzymology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D051381:Rats
D006913:Hydroxysteroid Dehydrogenases; D042842:11-beta-Hydroxysteroid Dehydrogenases; C003552:11-dehydrocorticosterone; D003345:Corticosterone